Nanowire Frontiers: Materials and Devices

申请者将开发III-V族半导体纳米线(NW)，用于三种应用--光伏、热电和Betavavoltaics--所有这些都与能源生产有关。半导体纳米棒代表了一类新的材料，它将传统薄膜技术的二维特性扩展到下一代光电子器件的三维空间。光伏(PV)设计中的核心挑战是在太阳能光谱中存在的非常广泛的波长范围内将太阳光转换为电能的成本效益。为了克服现有平板硅(Si)光伏电池的局限性，申请人正在开发可以直接在硅太阳能电池上生长的特意设计的III-V半导体NW，以提高其效率。这项提案将继续申请者对NW光伏的研究计划，使用离轴电子全息术来确定NW中的掺杂，这是实现这项技术的关键挑战之一。虽然光伏设备将有效地将可见光和近红外光转换为电能，但热电效应可以提供一种将更长的红外波长转换为有用电能的方法。在他研究基于NW的光伏器件的过程中，申请人发现了半导体NW的一种新特性，即其直径相关的光捕获特性和高效的光热转换，这可能对热电发电机(TEG)非常有用。在该项目中，申请人正在进行的西北光伏研究将扩展到使用垂直排列的InSb纳米线阵列的TIG，其中热电效率预计将比现有器件高得多。最后，Betavoltaic(BV)设备使用高能电子(β粒子)通过碰撞电离在半导体中产生电子-空穴对，从而直接产生电能。它们类似于光伏设备，但用β粒子取代了光子，因此是申请人光伏研究的自然延伸。我们建议在硅衬底上制备用于改进的BV电池的磷化镓(GaP)NW，提供比同等的Si BV器件更高的β捕获效率和更高的电压。这项研究可能的商业化产生了一个显著的好处--特别是开发可能为未来能源技术带来优势的纳米设备。对于加拿大来说，这一提议是一个机会，使其成为世界上第一个开发颠覆性技术的国家，这些技术将在大型市场产生竞争优势。这项提议还将为希望在加拿大光电子行业建立职业生涯的年轻研究人员提供一个独特的培训机会，因为加拿大光电子行业需要持续供应高素质的人才(HQP)。

The applicant will develop group III-V semiconductor nanowires (NWs) for three applications - photovoltaics, thermoelectrics and betavoltaics - all related to energy generation. Semiconductor NWs represent a new class of materials that extends the two-dimensional nature of conventional thin film technologies into the third dimension for the next generation of optoelectronic devices. The central challenge in photovoltaic (PV) design is the cost-effective conversion of sunlight to electricity over the very broad range of wavelengths present in the solar spectrum. To overcome the limitations of existing flat panel silicon (Si) PV cells, the applicant is exploiting intentionally engineered III-V semiconductor NWs that can be grown directly on Si solar cells to boost their efficiency. This proposal will continue the applicant's research program on NW PV by using off-axis electron holography to ascertain the doping in NWs, which is one of the key challenges in realizing this technology. While PV devices will efficiently convert visible and near-infrared light into electrical power, the thermoelectric effect can provide a way to convert longer infrared wavelengths into useful electrical energy. During the course of his work on NW-based PV devices, the applicant discovered a new property of semiconductor NWs in their diameter-dependent light trapping properties and highly efficient photo-thermal conversion, which could be very useful for thermoelectric generators (TEGs). In this project, the applicant's ongoing NW PV research will be extended to TEGs using arrays of vertically ordered InSb nanowires, where the thermoelectric efficiency is predicted to be considerably higher compared to existing devices. Finally, betavoltaic (BV) devices use energetic electrons (beta particles) to create electron-hole pairs in a semiconductor by impact ionization for direct generation of electrical power. They are similar to PV devices but replace photons with beta particles, and are therefore a natural extension of the applicant's PV research. We propose to fabricate gallium phosphide (GaP) NWs on Si substrates for improved BV batteries by offering a higher efficiency of beta capture and larger voltage than equivalent Si BV devices. A significant benefit arises from likely commercialization of this research - in particular, development of nanodevices that might yield advantages for future energy technologies. This proposal is an opportunity for Canada to be the first in the world to develop disruptive technologies that will yield a competitive edge in large markets. This proposal will also provide a unique training opportunity for young researchers wishing to establish careers in the Canadian optoelectronics industry where a continual supply of highly qualified personnel (HQP) is needed.